Various keystroke devices exist in the art. The most prevalent keystroke device is a computer keyboard. The keys of a standard computer keyboard are merely switches electronically indicating only a depressed state. Therefore, no signal is output or indicated by the keyboard when a keyboard is at rest, and a signal corresponding to depressed key(s) is output or indicated only when at least one key is depressed sufficiently far to “set off” the switch of that key or the switches of that set of keys.
A typewriter also has a keyboard, which can be mechanical and/or electronic. Like the computer keyboard, actuation (e.g., depression) of a key is intended to print a character. In electronic typewriters, when a key is actuated sufficiently far, a signal is sent to a processor to have the corresponding key(s) printed on the typing medium (e.g., paper). Mechanical typewriters are similar to electronic typewriters, but with one significant difference. Mechanical typewriters connect the key of the keyboard directly to the hammer containing the corresponding character to be printed on the page. Such a connection typically places the key at the end of a lever connected to a fulcrum and, when the lever is depressed at a proximal end, the distal end of the lever forcibly contacts or causes a hammer to pivot its distal end towards the page. A printing ribbon is disposed between the page and the end of travel of the hammer and a character formed at the end of the hammer is printed on the paper because the raised character presses the printing ribbon against the page. Because such an assembly is a mechanical connection dependent upon the pressure imparted by the user, the hammer can hit the page with varying degrees of force. A relatively hard contact produces a clearly printed character on the page. In contrast, a relatively soft contact may produce a lightly printed character, which also can be referred to as a “shadow.” For mechanical typewriters, it is more desirable to have clearly printed characters than to have shadow characters. Therefore, improvements were made over the history of mechanical typewriters to guarantee relatively uniform contact between the hammer and the page, which improvements were, thereafter, incorporated into most electronic typewriters.
Another keystroke device can be found on stenographic devices. The most modern stenographic devices are entirely electronic and virtually immediately translate the stenographic key actuations into an accurate written representation of the spoken word. These modern devices are analogous to the electronic typewriters and computer keyboards in that a specific actuation of a key or set of keys will cause a clear printing or storage of the corresponding character or set of characters. Insufficient depression of a key(s) will not generate any output. Alternatively, depression of a set of keys (which is common for stenographic writing) where one or more keys is sufficiently actuated but one or more other key(s) is insufficiently actuated will generate an output that does not correspond to the stenographers' intended output. Thus, the stenographer or computer associated with the stenographic device might not be able to accurately translate the inadequately actuated key(s) depending upon what was actually output to the paper or the electronically stored file.
The earlier stenographic devices provided an advantage over the modern stenographic devices. The older devices gave a stenographer some ability to determine a correct output from an incorrect input because these older mechanical devices printed the output on the paper in varying degrees of lightness. Stenographers refer to a lightly printed output as “shadow” output. So, if an intended output was lightly printed on the stenographic paper, that stenographer might have been able to determine what was intended during the original dictation and correctly translate the spoken word in the final transcript. Modern stenographic devices, however, are not able to electronically understand or store shadow output. If the stenographer does not actuate a key adequately, then no output is generated. And, if keys of a set of keys are actuated in varying degrees, then incorrect output is transcribed.
Stenographic devices also provide the user with the ability to physically adjust the depression actuation level for each stenographic key. In this way, when the user has a “strong” finger, the adjustment may be relatively lower because that finger presses the key down far. In contrast, when the user has a “weak” finger, the adjustment may have the actuation level be relatively higher because that finger does not press the key down as far as the “strong” finger presses other keys. Even with such adjustments, it is possible for the user to mis-adjust one or more of the keys. In such a situation, subsequent stenographic writing will be incorrect as it will include additional strokes where the level was set too high and will not include some strokes when the level was set too low.
Other problems stenographers have faced for many years are referred to as “stacking” and “splitting.” Either “stacking” or “splitting” results when a reporter presses several keys simultaneously and not all keys make contact with the sensing mechanism at the same time or are released at the same time. Stacking refers to a situation where multiple keys are pressed at the same or substantially the same time and are erroneously recorded as a single keystroke. Splitting refers to a situation where one keystroke is recorded as two keystrokes.
Since traditional keyboards can only record “on” and “off” values, the prior art has relied on simple timing algorithms to try to minimize stacking problems. More advanced versions of stenographic software provide “anti-stacking” algorithms. However, presently-known algorithms can cause the opposite problem to occur, i.e., splitting.
Therefore a need exists to overcome the problems with the prior art as discussed above.